Finally, the U.S. government is waking up to the realization that it cannot jail its way out of a drug problem.

President Obama's Department of Justice last year stopped making the problem worse, easing mandatory minimum sentencing in some cases. Last week, it offered a relatively narrow window for retroactive review. The DOJ laid out criteria for a new and welcomed opportunity for inmates who have served at least a decade for low-level, nonviolent offenses to apply for clemency.

Decades of adherence to failed War on Drugs policies has helped make the U.S. the world's largest jailer, with only 5 percent of the planet's population but 25 percent of its inmates. Of the nearly 217,000 federal inmates, half are incarcerated for drug crimes, according to the Bureau of Prisons. Yet drug usage has risen 2,800 percent since the War on Drugs began in 1971.

That absurd juxtaposition has forced cities, including Seattle, and states, led by Washington and Colorado, to form a controlled revolt against marijuana laws, the low-hanging fruit of drug-policy reform.

But the federal government, until recently, has mostly ignored the clamor. Congress in 2010 finally ended a disparity in cocaine-sentencing laws that sent mostly African-American users of crack to prison for two years longer, on average, than mostly white users of powder cocaine. Congress, locked in dysfunction, hasn't made that law retroactive, or done anything else toward meaningful drug reform.

Obama and Attorney General Eric Holder are making an end run around the legislative branch by turning to clemency, the tool of the executive.

How far they are willing to go is an open question. Criteria for this clemency initiative are vague, requiring no "significant" criminal history and "demonstrated good conduct" in prison. Used broadly, about 7,000 or more inmates could be freed. Expect fewer.

In the meantime, Congress remains wedded to failed drug policies.

Members of Congress should wake up and realize drug-sentencing reform is a populist issue: More than half of Americans favor legalizing marijuana. And the issue is increasingly a bipartisan affair. Texas Gov. Rick Perry, a likely GOP presidential candidate, advocated to "shut prisons down" at the recent Conservative Political Action Conference. Sens. Dick Durban, D-Ill., and Mike Lee, R-Utah, are co-sponsors of the Smarter Sentencing Act, which would make retroactive the 2010 crack cocaine sentencing fix.

Obama and Holder, the first African-Americans to hold either job, speak eloquently about communities of color hollowed out by the racially disproportionate effect of the War on Drugs. Good for them for leading. They shouldn't be alone.